Brain Computed Tomography Compared with Facial 3-Dimensional Computed Tomography for Diagnosis of Facial Fractures

The Adelaide Facial Bone Rule: A simple prediction model and clinical guideline for the presence of facial fractures using CT brain scans in victims of minor trauma

BACKGROUND

Facial fractures bleed, resulting in high-density fluid in the sinuses (haemosinus) on computed tomography (CT) scans. A CT brain scan includes most maxillary sinuses in the scan field, which should allow detection of haemosinus as an indirect indicator of a facial fracture without the need for an additional CT facial bone scan, yet no robust evidence for this exists in the literature. The aim of this study was to determine whether the presence of haemosinus on a CT brain scan, alone or in combination with other clinical information, can predict the presence of facial fractures.

METHODS

1231 adult patients, who had both brain and facial CT scans performed on the same day, were selected from a seven year period. Patients were eligible if scans were requested for trauma. Brain and facial scans were reviewed separately for the presence of facial fractures, haemosinus, emphysema and intra-cranial haemorrhage. Prediction modelling was used to assess whether findings from brain scans could be used to identify patients requiring further CT scanning.

FINDINGS

The full prediction model included four predictors and showed excellent discrimination (AUROC 0.982; 95 % CI 0.971 - 0.993). A simplified model, more suitable for clinical implementation, used only facial fractures and haemosinus as predictors. This model showed only marginally poorer discrimination (AUROC 0.964; 95 % CI 0.945 - 0.983) and excellent performance on other measures.

CONCLUSION

Based on the excellent performance of the simplified prediction model, we present the Adelaide Facial Bone Rule: The absence of blood in the sinuses or facial fractures on a CT brain scan means a CT facial bone scan does not need to be routinely performed in the setting of clinically-determined minor trauma.

Clinical and radiographic predictors of the need for facial CT in pediatric blunt trauma: a multi-institutional study

Background

Facial injuries are common in children with blunt trauma. Most are soft tissue lacerations and dental injuries readily apparent on clinical examination. Fractures requiring operative intervention are rare. Guidelines for utilization of maxillofacial CT in children are lacking. We hypothesized that head CT is a useful screening tool to identify children requiring dedicated facial CT.

Methods

We conducted a multicenter retrospective review of children aged 18 years and under with blunt facial injury who underwent both CT of the face and head from 2014 through 2018 at five pediatric trauma centers. Penetrating injuries and animal bites were excluded. Imaging and physical examination findings as well as interventions for facial fracture were reviewed. Clinically significant fractures were those requiring an intervention during hospital stay or within 30 days of injury.

Results

322 children with facial fractures were identified. Head CT was able to identify a facial fracture in 89% (287 of 322) of children with facial fractures seen on dedicated facial CT. Minimally displaced nasal fractures, mandibular fractures, and dental injuries were the most common facial fractures not identified on head CT. Only 2% of the cohort (7 of 322) had facial injuries missed on head CT and required an intervention. All seven had mandibular or alveolar plate injuries with findings on physical examination suggestive of injury.

Discussion

In pediatric blunt trauma, head CT is an excellent screening tool for facial fracture. In the absence of clinical evidence of a mandibular or dental injury, a normal head CT will usually exclude a clinically significant facial fracture.

Level of evidence

III.

Comparative and retrospective evaluation of the predictive performance of optic nerve sheath thickness and optic nerve sheath diameter for traumatic brain injury using facial computed tomography

OBJECTIVE

To evaluate the predictive performance of optic nerve sheath thickness (ONST) on the outcomes of traumatic brain injury (TBI) and to compare the inter-observer agreement To evaluate the predictive performance of optic nerve sheath thickness (ONST) for traumatic brain injury (TBI) and to compare the predictive performance and inter-observer agreement between ONST and optic nerve sheath diameter (ONSD) on facial computed tomography (CT).

METHODS

We retrospectively enrolled patients with a history of facial trauma and who underwent both facial CT and brain CT. Two reviewers independently measured ONST and ONSD of each patient using facial CT images. Final brain CT with clinical outcome was used as the reference standard for TBI. Multivariate logistic regression analyses, receiver operating characteristic (ROC) curves, and intraclass correlation coefficients were used for statistical analyses.

RESULTS

Both ONST (P=0.002) and ONSD (P=0.001) on facial CT were significantly independent factors to distinguish between TBI and healthy brains; an increase in ONST and ONSD values corresponded with an increase in the risk of TBI by 8.9- and 7.6-fold, respectively. The predictive performances of the ONST (sensitivity, 96.2%; specificity, 94.3%; area under the ROC curve, 0.968) and ONSD (sensitivity, 92.6%; specificity, 90.2%; area under the ROC curve, 0.955) were excellent and exhibited similar sensitivity, specificity, and area under the curve (P=0.18-0.99). Interobserver and intraobserver intraclass correlation coefficients for ONST were significantly higher than those for ONSD (all P<0.001).

CONCLUSION

ONST on facial CT is a feasible predictor of TBI and demonstrates similar performance and superior observer agreement than ONSD. We recommend using ONST measurements to assess the need for additional brain CT scans in TBI-suspected cases.

Optic nerve sheath diameter on facial CT: a tool to predict traumatic brain injury

PURPOSE

To evaluate and compare the optic nerve sheath diameters (ONSDs) of facial trauma patients as observed on facial CT and brain CT, and to evaluate the predictive performance of ONSD as seen on facial CT for traumatic brain injury (TBI).

METHODS

We retrospectively enrolled 262 patients with facial trauma who underwent both facial CT and brain CT. Two reviewers independently measured ONSD at 3 mm (ONSD3) and 10 mm behind the globe (ONSD10) for each patient on both CT scans. Final CT reports with clinical progress notes were used as the reference standard. Statistically, multivariate logistic regression analysis, receiver operating characteristic (ROC) curves, and intraclass correlation coefficients (ICCs) were used.

RESULTS

Eighty-seven (33.2%) patients were diagnosed with facial fracture, and 21 (8.0%) were diagnosed with intracranial haemorrhage. Neither reviewer observed significant differences (p = 0.15-0.61) between facial CT and brain CT when comparing ONSD3 and ONSD10. ONSD3 on facial CT was a significantly independent factor for distinguishing TBI from negative brain CT scan (p = 0.001); as ONSD3 increased, the risk of TBI increased 8.1-fold. ONSD3 ≥ 4.13 mm exhibited the highest area under the ROC curve (AUC) for predicting TBI (AUC, 0.968; sensitivity, 90.5%; specificity, 98.8%). There were good or excellent interobserver agreements for all measurements (ICC, 0.750-0.875).

CONCLUSION

ONSD3 as determined by facial CT is a feasible predictive marker of TBI in facial trauma patients. It can assist emergency physicians in deciding whether immediate further brain imaging is warranted.